Tip of the Week: December 2004 Archives

Black point. Objects in the foreground tend to have a lower black point that objects in the background. This is usually the case with extreme environments; matte paintings, set extensions, and also when CGI is composited into live action.

One of the rules is to match the black point of your CG to the black point of your film plate. You would never have a black point that is lower in the background than it is in the foreground. You can sample the color values of the darkest dark in your film plate and compare it to your darkest dark in your CGI. Do they match? Is one darker than the other? The color values may not be visible to you, but bump up that gamma on your monitor or TV. You're sure to see some discrepancies.

While watching The Two Towers and Return of the King, several of these black point issues jumped out at me. These scenes include Merry and Pippen on the back of Treebeard as he walks through Fangorn Forest, the Ents attacking Isengard, and the guard tower at the top of the pass after Frodo and Sam are attacked by Shelob.

Reference. noun. A work frequently used as a source.

In visual effects, this is the most frequently used word when trying to recreate realistic environments and interactions. Sometimes your reference may not be a realistic environment either. It could be a concept painting, an animation, pre-visualization, and so forth. Regardless, it's something you should always have when creating your shots.

Even in a wholly 3D created film, how do the interactions between characters or environments convey the sense of being there? Are their shadows in the right place? Does the light illuminate features that should or should not be there?

Only by analyzing reference will you be able to set the mood of your shot, and add subtle nuances to it. Even if your shot is one of many in a sequence, your references are the surrounding shots, the shots that contain no visual effects surrounding your shot.